Polyphase oscillation generator



Aug. 21, 1934.

E. D. M ARTHUR 1,971,193 POLYPHA SE OSCILLATION GENERATOR Filed May 20, 1950 Inventor: Elmer" D me Arthur His Attotkey.

'ture corresponds to the number Patented Aug. 21, 1934 1,9 71,19a I W POLYPHASE osommrron cansm'ron I Elmer D. McArthur, SchenectadyN. Y., assignor' I to General Electric Company, a corporation of p New York Application May 20 1930, Serial. No. 454,170 I,

7 Claims. 1(c1. z so ss My invention relates to generators of poly phase high'frequency electromotive force and it has forits object to provide a generator oi"; the type indicated which is or" more simple and economical construction than those of the prior art.-

A further object of the invention is to provide an oscillation generator of the type indicated employinga single electron discharge device of simple construction through action of which polyphase oscillations'are produced upon the circuits associated withthe electrodes thereof.

Still a further object of the invention is to provide an arrangement whereby an electron discharge device oi the magnetic field divided, or split, anode type, may be utilized'for the production of 'polyphas'e high-frequency oscillations, the anode structure of the discharge device being divided in accordance withthe number of phasesto be produced. Still a further object of" the invention is to provide a system in which polyphase oscillations are produced through action of a single electron discharge device and which at the same time, avoids the-use of agrid structure within the discharge device and coupling circuits between the difierent anodes and their corresponding grids to produce a regenerative action sufficient to sustain oscillations. Another object of theinvention is to provide a system of the type indicated which is particularly adapted to produce polyphase oscillations ofshort wavelength.

The novelieatures which I believe to be characteristic of my invention are set forth with particularity in the appended claims; My-in-' venticn 'itself however, both as toits organization and method of operation, together with further objects andfad'vantages thereof; may best be understood byreference to the following description takenin connection with the accompanying drawing in whichiigs. 1, 2 and 3 represent different embodiments of my invention. M Referringto Fig. 1 of the drawing, Ihave shownthereinan electron discharge device 1 havingan anode structure in the form of a cylinder', this cylinder being. divided longitudinally thereof into a number of anode segments-2, 3, i. The number of segments of the anode strucoffphases of the oscillations to'be produced. A cathode 5 is shown extending longitudinally of thedischarge device along the axis of the anode cylinder;

" This cathode is arranged to be heated by means or a source of electromotive force 6'through-a control resistance ranged about the 7; A field winding 8 is at electron discharge device and is energizedfrom a source of unidirectional eleci tromctive force 3' through a control resistance 10, the winding being so disposed about the dis} charge device thatthe lines of force extend within the anode cylinder and-substantially parallel with the cathode. -f g The circuit arrangement wherein the polyphase oscillations are produced, comprises a plurality, of inductances 1'1, 12 and 13. Since as shown in the drawing the system'is adapted to produce 3'phase electromotive force; three of these inductances are shownfthese inductances being connected inv', the outer terminals ofthe Ybeing connected tothe anodes 2, 3 and 4 respectively, andthe neutral point ofthe Y being connected tlnough'a source of unidirectional potential 14 to the cathode. By means of this source of potential-all oi the anodes are main-'' tamed-at a constant average positive unidirectional potentialwithrespect to the cathode. i

Connected'between the outer terminals ofthe Y are a plurality of condensers 15, 16 and 17. These condensers, as will be apparent from the drawing, are connected in parallel with thein-i ternal capacity of the discharge device between adjacent electrodes to which they are connected. Accordingly whenthe deviceis operated at .very high frequencies these condensers may be omitted. In fact, at very high frequency the in-i ductances 1'1, .12. and 13.may comprise merely the inductances of the conductorsleadingto the anodes. V 4

,1Asthus arranged itwill be seen that the cir-. cuit comprises a plurality of oscillatory circuits, one of which comprises theinductancesl1 and 12;;and the condenser '15; another compris ing h ind ctan e l anal ndqt peudenser 6 an the th r om r n e-ind t'ances l2 and 1,3 and the condenser 17,

If we. assume-tat the cathode of,

charge-device is heated "to incandescence, that the source of anode electromotiverforce 14 is adjusted to a value suitable for-"operation, and that the field intensity isthen increased, itwill beiound that "over a range of field intensities oscillations will be excited in the circuitsabove described. If weassume'that prior" to the initif ation of these oscillations ele'ctronsjare' flowing from the cathode to each of the'j anodes in 'an extent sufficientto' cause equal currentsto new in the-"inductances I1, 312 I and 13, fandTthe'ri through-action of 'two' of the anodesfas for ex its rib

ample anodes 2 and 3, oscillations are excited in one of the above circuits, as for example the circuit 11, 12, 15 thereby causing one of the anodes 2, 3 to become more positive and the other less positive, it can readily be understood that the current conditions within the discharge device will be so disturbed as to cause a change of current in inductance 13, thereby exciting oscillations in the other two oscillatory circuits. I have found that these oscillations are sustained in the various circuits and have a definite polyphase relation with respect to each other.

The arrangement shown in Fig. 2 is similar to that shown in Fig. 1 with the exception that the inductances 11, 12 and 13 are connected in delta rather than in Y. In this case the mid points of all of the inductances are connected together and to the positive side of the source of potential 14. Connected in parallel with each of the inductances 11, 12 and 13 are the condensers 15, 16 and 17, the oscillatory circuits in this case comprising the elements 11, 15; 12, 16, and 13, 17. Each of these circuits is resonant at the frequency of the oscillations to be produced and connected as shown oscillate in polyphase relation. The arrangement shown in Fig. 3 differs from that shown in Fig. 1 only in that the inductances 11, 12 and 13 ar'earranged upon a suitable non-conducting frame 18 which suitably may be of cylindrical form.

The polyphase oscillations produced in the circuits may be supplied to a suitable load circuit by means of any desired and well known form of coupling. In Fig. lthe inductances 11, 1:2 and 13 are shown as comprising the primary windings of single phase transformers, the secondary windings of these transformers being connected in Y and connected to a suitably polyphase load circuit 19. It will of course be widerstood that the secondary wind il gs may be connected either in Y or in delta.

In Fig. 3 I have shown each phase of the load circuit 19 coupled to a corresponding phase of a polyphase oscillatory circuit through a suitable 7 coupling condenser 20,.

While in each of the figures of the drawing I have shown an electron discharge device having three anodes and which is thereby adapted in association with the circuits described to produce three phase oscillations, it will. of course be understood that there maybe any greater number of anodes in accordance with the number :of phases of the oscillations which it is desired to produce. a

It will thus be seen that the system in accordance with my invention possesses great advantages in the simplicity of the arrangement in that the oscillations are excited through action of the magnetic field upon the electrostatic conditions within the discharge device as distinct from any regenerative arrangement employing grids within the discharge device and associated anode to grid coupling circuits. Thus in 'the system described the anodesare adjacent to the cathode, there being no grid structure interposed between the cathode and anodes. Further, it has been found that discharge devices of the type described are capable of producing oscillations of short wave length. Thus the system istparticularly adapted for use in short wave radiation systems particularly in connection with directive beacon systems such as may be utilized for directing aircraft, where it is' desired to radiate directionally in three or more directions rather than in two directions as in present practice.

While I have shown particular embodiments of my invention, it will of course be understood that I do not wish to be limited thereto since many modifications may be made both in the circuit arrangement and in the instrumentalities employed, and that I therefore contemplate by the appended claims to cover all such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. The combination, in a system for producing polyphase igh frequency electromotive force, a polyphase circuit, means including a single electron discharge device having at least three electrodes for exciting oscillations in said circuit,

I each of said electrodes being included in a corresponding phase of said circuit and means for producing a magnetic field within said discharge deviceto control the action thereof thereby to cause polyphase high frequency electromotive force to be produced in said polyphase circuit, said magnetic field being unidirectional during the production of said polyphase electromotive force. 7

l 2. The combination, in a system for producing polyphase electromotive force, a polyphase circuit, means including a single space discharge device for exciting oscillations in said circuit, said space discharge device comprising a number of anodes greater than two, and a cathode, said anodes being arranged about said cathode and each anode being connected to one phase of said polyphase circuit, means to produce a magnetic field between said anodes whereby polyphase oscillations are produced in said polyphase circuit, and means whereby the frequency of said polyphase oscillations is dependent upon the frequency characteristics of said polyphase circuit.

3. In combination, an electron discharge device, having a centrally located cathode and a number of anodes greater than two disposed about said cathode, means for producing a unidirectional magnetic field between said anodes and cathode, means for supplying a positive potential to each of said anodes with respect to said cathode, a polyphase circuit connection including said anodes and cathode whereby when said magnetic field is produced between said electrodes alternating electromotive force is produced between each anode and the cathode, and the electromotive forces on the different anodes bear a polyphase relation to each other, and means whereby the frequency of said polyphase electromotive forces is dependent upon the frequency characteristic of said polyphase circuit.

4. In combination, an electron discharge device having a number of anodes greater than two, and a cathode, said anodes being disposed about said cathode in the form of a cylinder; means for producing a magnetic field within said cylinder and extending longitudinally thereof, a polyphase circuit arranged to oscillate in each phase, and each phase being connected to one of said anodes whereby polyphaseoscillations are excited in said circuit discharge device.

5. The combination, in a system for producing polyphase high frequency electromotive force, an electron discharge device having a centrally arranged cathode and a number of anodes greater than two arranged about said cathode, a polythrough action of said phase circuit, each phase of said polyphase circuit being connected to a corresponding one of said anodes, means to tune said polyphase circuit to the frequency of oscillations to be produced and means to produce a constant magnetic field within said discharge device thereby to cause the production of polyphase oscillations in said polyphase circuit.

6. The combination, in a system for producing polyphase high frequency electromotive force, an electron discharge device having a centrally arranged cathode and a number of anodes greater than two arranged about said cathode, a polyphase circuit, each phase of said polyphase circuit being connected to a corresponding one of said anodes, means to produce a magnetic field within said discharge device thereby to cause the production of polyphase oscillations in said polyphase circuit, said means being so arranged as to produce a magnetic field having intensity independent of oscillations in said polyphase circuit.

7. The combination, in a polyphase oscillation generator, of an electron discharge device having a number of anodes gerater than two arranged about a cathode, a polyphase circuit connected to said anodes, means whereby said polyphase circuit is tuned to the frequency of oscillations to be produced, and means to cause oscillations to be produced in said polyphase circuit having a frequency dependent upon the tuning of said polyphase circuit said means including means to produce a magnetic field between said anodes and cathode.

ELMER. D. MCARTHUR. 

